Audio and Video Sync

[scaught101]

Hey, all.

On our 850, I am noticing a clear syncing problem between audio and video upon review of the recorded video. It seems worse sometimes versus others, but it's clearly there. If I bring the MPG file into SpeedEdit, I have to move the MPG's audio file a bit to get it to sync w/ the action (talking heads, mostly).

I remember (barely) a setting on the SD systems that fixed this for the recorded files. Can somebody help with this?

Thanks,

[jandw]

I noticed something similar! We are currently testing the XD300 to see if it is OK to put in our satellite-truck and so transform them to a small multicam-setup using ENG-crews.

But: when audio is fed through the XD300, we see audio being off about 1,5 frames with the video. Sources are genlocked!!

Off course, this can be easily solved: an audio-delay unit is easy and cheap. But it should be corrected internally in the Tricaster.

I'm sorry to say it, but small things like this keep the Tricasters a bit in the grey-zone for broadcast TV-techs. I'm a fan, but such small things should be taken care off.

[ACross]

I will double-check on this. I know that we looked at it in great detail before we shipped, but we will double check again.

Please email me any details that you have (e.g. is audio ahead of video, or vice versa).

Andrew

[Paul Lara]

when audio is fed through the XD300, we see audio being off about 1.5 frames with the video.

I spoke with our engineers.
They went back and double-checked this in significant detail and found the A/V offset (the difference in time between audio & video) can be from one-half to 1 frame, but normally closer to one-half frame. This is exactly what you would expect though a video device. Even when genlocked, unless you are very very careful (and have an oscilloscope to clock our genlock right).

If you feel there is a problem, please feel free to submit a bug report with full and exact instructions on how to reproduce it, with video mode, camera types, how you measured latency, etc.

NewTek can investigate this further if you need us to.